Department of Pharmacology, Harbin Medical University, Baojian Rd 157, Harbin 150081, Heilongjiang Province, People's Republic of China.
Hypertension. 2010 Apr;55(4):946-52. doi: 10.1161/HYPERTENSIONAHA.109.139519. Epub 2010 Feb 22.
Cardiac hypertrophy involves a remodeling process of the heart in response to diverse pathological stimuli. Both calcineurin/nuclear factor of activated T cells pathway and microRNA-133 (miR-133) have been shown to play a critical role in cardiac hypertrophy. It has been recognized that the expression and activity of calcineurin increases and miR-133 expression decreases in the hypertrophic heart, and inhibition of calcineurin or increase of miR-133 expression protects against cardiac hypertrophy. Here we tested the interaction between miR-133 and calcineurin in cardiac hypertrophy. Cardiac hypertrophy in vivo and in vitro was induced by transverse aortic constriction and phenylephrine treatment. mRNA levels were measured by using real-time PCR methods. Luciferase assays showed that transfection of miR-133 in HEK293 cells downregulated calcineurin expression, which was reversed by cotransfection with the miR-133-specific 2'-O-methyl antisense inhibitory oligoribonucleotides. These results were confirmed in cultured primary cardiomyocytes. miR-133 expression was downregulated, and calcineurin activity was enhanced in both in vivo and in vitro cardiac hypertrophy models. Treatment of cells and animals with cyclosporin A, an inhibitor of calcineurin, prevented miR-133 downregulation. Moreover, the antisense oligodeoxynucleotides against the catalytic subunits of calcineurin Abeta and the decoy oligodeoxynucleotides targeting nuclear factor of activated T cells transcription factor, a calcineurin downstream effector, increased miR-133 expression in cultured primary cardiomyocytes. Our data show that reciprocal repression between miR-133 and calcineurin regulates cardiac hypertrophy.
心肌肥厚是心脏对各种病理刺激的一种重塑过程。钙调神经磷酸酶/活化 T 细胞核因子（NFAT）通路和微小 RNA-133（miR-133）已被证实对心肌肥厚起着关键作用。已发现，在肥厚的心脏中，钙调神经磷酸酶的表达和活性增加，miR-133 的表达减少，而抑制钙调神经磷酸酶或增加 miR-133 的表达可预防心肌肥厚。在这里，我们检测了 miR-133 与钙调神经磷酸酶在心肌肥厚中的相互作用。通过横主动脉缩窄和苯肾上腺素处理诱导体内和体外的心肌肥厚。采用实时 PCR 方法测量 mRNA 水平。荧光素酶检测显示，在 HEK293 细胞中转染 miR-133 可下调钙调神经磷酸酶的表达，而用 miR-133 特异性 2'-O-甲基反义抑制性寡核苷酸共转染则可逆转这种作用。这些结果在培养的原代心肌细胞中得到了证实。miR-133 的表达下调，钙调神经磷酸酶的活性在体内和体外的心肌肥厚模型中均增强。用钙调神经磷酸酶抑制剂环孢菌素 A 处理细胞和动物可防止 miR-133 的下调。此外，针对钙调神经磷酸酶催化亚基的反义寡脱氧核苷酸和针对活化 T 细胞核因子转录因子的诱饵寡脱氧核苷酸（钙调神经磷酸酶下游效应物）可增加培养的原代心肌细胞中 miR-133 的表达。我们的数据表明，miR-133 和钙调神经磷酸酶之间的相互抑制调节心肌肥厚。
